Fluid recovery system

ABSTRACT

A thoracic cavity drainage device includes a first vessel having a plurality of chambers one of which is a regulated drainage chamber, and a separate transfer vessel which receives fluid collected in the drainage chamber of the first vessel. The chambers of both vessels are interconnected in a series by fluid passageways which cooperate to maintain a uniform range of suction in the drainage chamber while preventing passage of water into the drainage chamber and permitting a different level of suction in the transfer vessel. This operation is effective despite relatively large pressure and vacuum impulses caused by stripping of drainage lines, patient coughing, and the like, and despite discrete changes in the physical configuration of the system caused by disconnection of the transfer vessel, connection of the transfer vessel to an infusion line or the opening or closing of fluid lines and ports. A novel transfer vessel empties the drainage device and provides gravity reinfusion of the collected fluids. A mechanism within the transfer vessel provides an effective suction without vacuum connections or pressure regulating adjustments.

This application is a continuation of U.S. patent application Ser. No.255,764 filed on Oct. 11, 1988 and entitled "Improved Fluid RecoverySystem" issued as U.S. Pat. No. 4,988,342, which was acontinuation-in-part of U.S. patent application Ser. No. 020,449 filedMar. 2, 1987 and entitled "Chest Drain Device with Means for RecoveringBody Fluid", now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to drainage apparatus, and more particularly toapparatus for draining fluids such as blood from a body cavity and forthe reuse of such fluids.

Blood recovered from a patient's body cavity (autologous blood) offerssignificant advantages over blood from other humans (homologous blood).Autologous blood reduces the risk of adverse reactions and transmissionof infectious disease, has near normal oxygen carrying capacity and pH,conserves blood supplies, provides a readily available source ofcompatible blood; and provides cost savings. For these reasons, thepractice of reinfusing autologous blood, known as autotransfusion, isexpanding rapidly.

Autotransfusion may be used in the emergency room setting to recoverblood lost through chest trauma; in the operating room setting torecover blood shed during surgery; or in the intensive care setting torecover shed mediastinal blood following cardiac or other surgery.

Various devices have been developed to drain and collect fluids such asblood from a body cavity for subsequent autoinfusion. The following U.S.patents illustrate prior art developments in drainage and/orautoinfusion devices.

U.S. Pat. No. 3,559,647 Bidwell et al,

U.S. Pat. No. 3,683,913 Kurtz et al,

U.S. Pat. No. 3,853,128 Kurtz et al,

U.S. Pat. No. 4,018,224 Kurtz et al,

U.S. Pat. No. 4,112,948 Kurtz et al,

U.S. Pat. No. 4,443,220 Hauer et al,

U.S. Pat. No. 4,540,413 Russo,

U.S. Pat. No. 4,605,400 Kurtz et al.

In U.S. Pat. No. 3,853,128, for example, there is disclosed a drainapparatus of one piece unitary construction. The device includes acollection chamber for collecting fluids from a body cavity, a waterseal chamber for preventing passage of air from the atmosphere into thebody cavity, and a manometer chamber for regulating the degree of vacuumin the system. The collection chamber is connected by a thoracotomy tubeto the patient's pleural cavity. The device is connected to a suctionpump and the amount of liquid in the manometer chamber determines thedegree of vacuum imposed. A valve mechanism is provided in the waterseal chamber to permit the outflow of gases from the apparatus in theevent of a sudden increase in pressure in the device, such as may occurwhen the patient coughs.

One difficulty encountered with the prior art devices is that noprovision is made for autoinfusing simultaneously with draining. Adevice which would allow autotransfusion simultaneously with drainingwould have significant advantages over prior art devices, especially inthe emergency room and operating room settings. Elimination oftime-consuming intervening steps between collection, transfer of blood,and autotransfusion would streamline the autotransfusion tasks ofmedical personnel and enhance the utility of autotransfusion.

The prior art drainage devices generally cannot be used tosimultaneously collect blood from the pleural cavity and autotransfuse,because there is no provision in prior art devices for automaticregulation of negative pressure during autotransfusion. Duringautotransfusion, as fluid exits the collection chamber, remaining fluidvolume drops and pressure negativity increases. It is important tomaintain pressure negativity within a relatively narrow range to keepbleeding to a minimum and to prevent damage to intrathoracic tissue.

One approach to the solution to this problem is to provide a chambercomprising a collapsable bag whose volume can change as required. SeeU.S. Pat. No. 4,443,220. Such blood bags may be removed from thedrainage device when full and placed on a stand to effect reinfusion,but these devices are incapable of simultaneous drainage and reinfusion.Another approach is to provide a mechanical pressure regulatingmechanism in communication with a collection chamber which functions toregulate the subatmospheric pressure in the collection chamberindependent of the chamber's effective volume. See U.S. Pat. No.4,548,413. Such mechanical pressure regulating mechanisms are costly andoften unreliable.

The relative underpressures suitable for drainage of the thoracic cavityare in the range of several centimeters of water, representing apressure difference of well under 0.01 atmospheres. However, thedrainage tube from a patient may itself have a significant volume; as aresult, the process of "stripping" the tube to clear its lumen byforcing blockages along the tube may introduce substantial fluctuationin pressure into the drainage vessel. Further, the placing of a separatecollection vessel in the suction drainage system alters system volume.For these reasons, the combination of known drainage devices with aseparate fluid collection chamber for collecting a portion of fluid forreinfusion cannot be expected to maintain a uniform suction at thedesired low level. Moreover, known system for fluid collection are notadapted for simultaneously both draining fluids and transferring thedesired fluids into the circulatory system.

There accordingly exists a need for a reliable, inexpensive, simple touse, disposable device which allows simultaneous collection andautoinfusion of fluids such as blood while providing dependableregulation of the negative pressure applied to the collection chamber,and which can be used intraoperatively or post operatively.

SUMMARY OF THE INVENTION

The present invention provides a disposable unitary structure forsterile collection of fluids from the thoracic cavity of a patient, andfor simultaneous reinfusing such fluids back to the circulatory systemof the patient. The apparatus comprises a rigid collection chamber forreceiving fluids from the pleural cavity, a U-shaped water seal chamberfor preventing unhindered passage of air from the atmosphere into thebody cavity, and optionally a manometer chamber for maintaining aselected subatmospheric pressure range in the collection chamber. Thecollection chamber has three ports: the first port is adapted forconnection to a tube for drawing fluids from the pleural cavity or awound or opening into the collection chamber; the second portcommunicates with the water seal chamber; and the third port, controlledby a valve, seal or diaphragm is adapted for connection with an infusionpump or separate reinfusion or transfer vessel for delivering fluidscollected in the collection chamber into the circulatory system of thepatient.

The device includes means for admitting air into the collection chamberwhen collection chamber pressure drops below a selected subatmosphericlevel, such as might occur during reinfusion of fluids through the thirdport. The various means for maintaining an underpressure condition, suchas the water seal and manometer, are each configured to have arelatively broad and continuous response to pressure fluctuations. Thedevice is thereby operable to maintain a selected subatmosphericpressure range in the collection chamber during outflow of collectedfluid, and to permit reinfusion of fluids from the collection chambersimultaneously with drainage from the pleural or other body cavity intothe collection chamber.

In a preferred embodiment, this function is provided by a structureinterposed between one arm of the water seal chamber and the collectionchamber. The structure also prevents water siphoning into the collectionchamber as pressure therein decreases, and prevents water entrained inair bubbles passing through the water seal during reinfusion fromentering the collection chamber to contaminate the body fluids.Additional structure in one or more U-shaped water columns accommodatesextreme pressure fluctuation without impairing the water seal, andpermits fine control of relatively small suction ranges in normaloperation. In a preferred embodiment, the system includes aspring-loaded transfer vessel which connects to the third port toprovide a system wherein a single fluid connection adds or removes thetransfer vessel. No additional valving, vacuum connections or otherconnections are required, and the drain line from the patient is notdisturbed. Despite the significant changes thereby introduced in localpressure levels and total chamber volume, the desired suction level ismaintained and collected fluids are removed from the chamber withoutinterruption or system instability for disposal or reinfusion of thecollected fluids.

It is accordingly an object of the invention to provide a reliable,easily used, inexpensive and disposable drainage device capable ofsimultaneous collection and autoinfusion of collected fluids, and whichregulates subatmospheric suction pressure during both drainage andautoinfusion while minimizing introduction of ambient air into contactwith the collected and reinfused fluids. Another object is to provide aversatile device which functions effectively intraoperatively as asuction-powered drainage device, and post operatively may be used todrain the pleural and mediastinal cavities without inducing excessivebleeding or fluid exudation and without damaging intrathoracic tissue.

BRIEF DESCRIPTION OF DRAWINGS

For a fuller understanding of the nature and objects of the invention,reference should be made to the following detailed description and theaccompanying drawings, in which

FIG. 1 is a sectional view of a basic drain device according to theinvention;

FIG. 2 is a schematic diagram showing an autotransfusion circuitaccording to the present invention;

FIG. 3 is a front perspective view of a preferred system forimplementing an autotransfusion circuit similar to that of FIG. 2;

FIG. 4 is a sectional view of the drain device shown in the system ofFIG. 3;

FIG. 5 is a back view of the drain device shown in the system of FIG. 3;

FIG. 6 is a top view of the prototype drain device of FIGS. 3 and 5;

FIG. 7 is a side view from the collection chamber side of that draindevice;

FIG. 8 is a bottom view of that drain device;

FIG. 9 is a side view from the manometer chamber side of that draindevice;

FIGS. 10, 10A, 11 and 12 are front perspective views of four differentdrain devices embodying different aspects of the invention; and

FIG. 13 illustrates interior operating characteristics of the draindevice of FIGS. 3-9.

Throughout the description, like reference characters in respectivedrawn figures indicate corresponding parts.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Referring to FIG. 1, there is shown a chest drain device 10 which ispreferably of unitary construction, fabricated by adhering togetherrigid molded parts of plastic, at least some of which, as described infurther detail below, are transparent. The device generally comprises acollection chamber 12, a U-shaped water seal chamber 13, and a suctioncontrol or manometer chamber 14.

Blood and other fluids from a patient's body cavity enter drain device10 through a tube 26 attached to inlet port 11, and are collected incollection chamber 12 after passing through a gross filter 30 whichtraps macroscopic debris such as blood clots, bone fragments, and thelike entrained in the incoming fluid. Filter 30 preferably has anapproximate pore size of 80-270 microns, suitable for filtration of suchcontaminants as bone and other tissue not suitable for bloodtransfusion. Collection chamber 12 is preferably provided with graduatedmarkings (not shown) indicating the volume of fluid it contains.

Water seal chamber 13 provides a barrier to reflux of atmospheric airinto a patient's pleural cavity. Water seal chamber 13 is a U-shapedchamber having two arms 13a and 13b, and preferably is provided withgrommet 17 for filling with water via a syringe needle. Water sealchamber 13 preferably also has graduations to indicate fill level. Arm13a of water seal chamber 13 is of smaller cross-sectional area than arm13b, and communicates with collection chamber 12 via structure 113 andport 111. The under end of arm 13a has a vacuum port 18 for connectionto a source of vacuum. Water seal chamber 13 communicates with arm 14aof manometer chamber 14 through port 114. Arm 14b of manometer chamber14 is vented to the atmosphere through vented plug 15, which isremovable to allow filling of manometer chamber 14 with water. Manometerchamber 14 is preferably provided with graduated markings to indicatefill level. Arms 14a and 14b communicate via the narrow slits 109 inbubble indicator 110. The manometer chamber regulates vacuum by allowingair at atmospheric pressure to pass through the manometer water columnand bubble indicator into the water seal chamber. The amount of waterdisposed in manometer chamber 14 serves to regulate the subatmosphericpressure in chambers 12 and 13 generated by the vacuum source attachedto port 18. Specifically, when a vacuum source is connected to port 18,the subatmospheric pressure difference in the region of port 114 will beequal to the height in centimeters of the water column in arm 14a, undernormal operating conditions.

Certain respiratory conditions can cause a sudden increase in pressurewithin the pleural cavity. For example, a cough or an air leak into thepleural cavity can produce a substantially higher pressure within thepleural cavity; such pressure must be relieved to permit normalrespiratory function. Additionally, such a sudden increase in pressureis passed directly to the drain device by tube 26, and in a prior artdevice can force water out of the manometer chamber through vented plug15. This is undesirable, since upon return to lower pressure in thepleural cavity, a substantially lower vacuum will be imposed on thecavity due to the lower remaining water volume in the manometer chamber.The device 10 avoids this problem in part by providing, in addition tothe aforesaid port and water column structure, a self-regulating,diaphragm-type, positive pressure release valve 16, located in thevacuum line attached to port 18.

Near the bottom section of collection chamber 12 is disposed a fluidremoval port 19. The port includes a microemboli filter 24, preferably a20-40 micron filter. Tubing 20 is attached to port 19 and is fitted witha conventional clamp 21 which controls the flow of fluid from chamber 12into an infusion pump 28 (FIG. 2) or transfer/infusion vessel 50 (FIG.3).

The embodiment of the invention of FIG. 1 also includes an optionalvalve 40 disposed in a valve housing 42 which communicates betweenchamber 12 and the ambient atmosphere. A bacterial filter 44 disposed inhousing 42 assures that airborne microorganisms passing through valve 40do not contaminate fluid contained in collection chamber 12. Valve 40may comprise a manually operated valve, such as a pushbutton valve,which, when actuated, permits influx of air into chamber 12.Alternatively, valve 40 may comprise a check valve which opens inresponse to a preselected pressure differential on its opposite sides.The purpose of valve 40 is to provide alternative means for permittinginflux of air into chamber 12 to relieve excessive subatmosphericpressure which may develop in chamber 12 during use of the drainageunit.

Operation of the drain apparatus is best understood with reference toFIG. 2, a schematic of an autotransfusion circuit utilizing theinvention. In use, water seal chamber 13 is filled with water to apreselected level, and manometer chamber 14 is filled with water to alevel corresponding to a desired subatmospheric pressure. Thoracotomytube 26 is connected to the patient and to port 11, and vacuum from awall outlet or portable vacuum source is then applied to vacuum port 18.Vacuum modulated by air bled in through the manometer chamber is therebyapplied to the collection chamber 12, and to the thoracotomy tube 26,and fluids such as blood are drawn into collection chamber 12. Suchcollection may be utilized in the emergency room, operating room,intensive care or other post operative settings.

When used intraoperatively, a conventional suction head (not shown) issealed to the distal end of tube 26, and the surgeon periodicallyvacuums the patient's blood from the site of the incision. When usedpostoperatively, the thoracotomy tube 26 is implanted in a suitablelocation in the patient's body cavity, typically the pleural cavity, andfluid is withdrawn as it collects while a subatmospheric pressurecompatible with normal breathing is maintained in the pleural cavity andin collection chamber 12.

Body fluids entering chamber 12 pass through filter 30 which trapsparticulate matter, assuring that the liquids collected in chamber 12are free of macroscopic particles. Irregularities of the pressure inchamber 12 caused by coughing of the patient or "milking" of thethoracotomy tube 26 are accommodated automatically in the device bychanges in water levels within the columns 13a, 13b of the water sealchamber 13. Fluctuations in the vacuum source attached to port 18 aremodulated by the water in the manometers chamber 14 and positivepressure relief valve 16 which automatically permit influx or reflux ofair as required to maintain internal subatmospheric pressure in thenarrow range corresponding to the water columns.

In the system of FIG. 2, autotransfusion may be accomplished by openingclamp 21, thus permitting fluid to flow out through filter 24, port 19,along line 20, and into infusion pump 28, which returns fluids to thepatient via infusion line 29.

Referring again to FIG. 1, the present invention allows for automaticregulation of negativity during autotransfusion by virtue of thecooperation of port 111 through which water seal chamber 13 communicateswith collection chamber 12, and elements 113a through 113d ofself-bailing structure 113. As fluid is autotransfused through port 19,subatmospheric pressure in chambers 12 and 13 are equalized through port111 as air passes upwardly through chamber 13a, and water seal integrityis maintained by the structure 113, which prevents interchambersiphoning. Water rising as a column in chamber 13a and entrained as amist in air bubbles passing through the column is confined in thestructure 113 and returned to the water seal chamber. Similarly,elements 112a through 112f protect manometer integrity by preventinginterchamber siphoning effects between the manometer and water sealchambers.

For intraoperative use, the water seal chamber may or may not be chargedwith water, at the option of the physician. Suction can be controlledvia a wall outlet regulator, or via manometer chamber 14. In any case,use of the device in this manner provides more gentle suction levelsthan those attainable by prior art intraoperative drain systems.

Collected fluids can be reinfused on a continuous basis directly backinto the patient through filter 24 and infusion pump 28, because thegentle and continuous suction automatically provided by drain 10 iscompatible with the simultaneous outflow and inflow of blood fromcollection chamber 12.

In fact, because of this gentle suction regulation, collected blood maybe withdrawn and reinfused in accordance with the invention without useof any electrical infusion pump or other major equipment. FIG. 3 showssuch a non-mechanical autologous blood circuit.

A drain unit 10a substantially similar to the device of FIG. 1 has anoutlet 19a at the base of its collection chamber 12 to which a transfervessel 50 is connected to receive fluids collected in chamber 12.Transfer vessel 50 is a heavy plastic bag having an inlet 52, and anoutlet 51, as well as a vent 54 having a microporous filter 55 andclosure cap 56. Inlet 52 and outlet 51 are at opposed ends of the bag,with the top/bottom orientation defined by a hole 61b for hanging thebag in a vertical orientation. A pierceable sampling or medicationinjection port 57 is preferably also provided.

At the bottom of vessel 50 a separate microemboli filter 59 isinterconnected between port 51 and an infusion line. Shown in phantom isa spike connector 53 and large bore PVC infusion tubing 53a which, inthe preferred embodiment, are permanently connected to inlet 52 andadapted to couple with a mating diaphragm closure and spike-compatibleconnector extending from the outlet port 19a of the drain 10a. Beforeinterconnection of the drain and transfer vessel, connector 53 ismaintained in a sterile state in a sheath 54a formed on the ventmanifold 54.

Transfer vessel 50 is adapted to generate its own suction, andpreferably is a spring-loaded suction vessel, having an internalstructure of the type, for example, which is illustrated in U.S. Pat.No. 4,429,693. For purposes of describing the conventional aspects ofthis vessel, the disclosure of that patent is hereby incorporated hereinby reference. That patent shows a bag with an internal folding framewhich is urged apart by a coil spring to exert a force on opposite sidesof the bag, creating a strong and reasonably uniform suction. Anembodiment of that patented spring-loaded suction vessel is presentlymarketed by the Johnson and Johnson Company as its "J-VAC" suctionreservoir. In that device, a folding box-like internal frame placedabout a coil spring is normally maintained in a substantially flatposition by an internal latch. When the frame is slightly bent, thelatch mechanism releases, and opposing walls of the frame are thereafterurged to unfold under the influence of the spring, creating an effectivesuction of 0.05 to 0.10 atmospheres.

For the practice of this invention, the precise suction level is notimportant, so long as it is sufficient to overcome the draw ofcollection chamber 12. An appropriate vessel is achieved by modifyingthe above-described commercially available suction vessel to furtherincorporate a capped and filtered vent, a capped outlet port verticallyopposed to the vent, and preferably also a sampling port as shown inFIG. 3. In addition, the internal spring is suitably treated to meet USPblood computability specifications for contacting blood which is to bereinfused, and blood-compatible polymers or coatings are used for theinternal frame structure as well as the bag inner surface. For theparticular transfer vessel described, the level of suction developed bythe vessel, corresponding to a water column of twenty to fiftycentimeters, is sufficiently stronger than the levels maintained indrain 10a, to readily draw out any fluids from the collection chamber 12of the drain. The suction differential remains effective to drain thecollector 10a when transfer vessel 50 is suspended at any heightapproximately level with or below the top of drain 10a.

Operation of the system for collecting fluids and reinfusing thecollected fluid proceeds as follows. First, the drain 10a is set up byfilling the manometer and water seal chambers to an appropriate levelfor achieving the desired suction. This level will depend on whether thedevice is used intraoperatively, or, if post operatively, on the natureof the thoracic drainage site and whether there is leakage into thethoracic cavity. Next, the vacuum source is connected, and then thedrain line to the patient is connected. During this period, the outletport is closed, or, if vessel 50 is connected, the port may be open solong as all vents and outlets of vessel 50 are closed and its springmechanism is latched in the retracted position.

When a sufficient volume of blood for reinfusion has collected, vessel50, if not already attached, is attached and its spring mechanismreleased. This draws the collected blood through port 19a from drain 10ainto vessel 50.

Thereafter, the line from the drain outlet port is clamped, and vessel50 is removed and its inlet is closed. The outlet of vessel 50 is thenconnected through a microemboli filter to an infusion line, and itscontents are redelivered to the patient. This may be accomplished byplacing a pressure cuff about vessel 50 for bolus delivery.Alternatively, it may be accomplished by hanging the vessel at asuitable height above the patient, opening the filtered vent, anddelivering the vessel contents by gravity infusion. For the bolusdelivery, it is not necessary to disconnect the vessel from drain 10a,but only to clamp the PVC connecting line. However, it is generallyintended that transfer vessel 50 not be relatched or re-used, so it ispreferable to simply disconnect the transfer vessel. Once disconnected,a second vessel 50 may be connected to receive a further unit ofcollected blood, and to similarly reinfuse the blood.

Returning to the drain 10a of FIG. 3, several features of the preferredembodiment are shown in the front perspective view, and are noted herebefore proceeding to a more detailed discussion of the interior shape ofthe preferred drain. Drain 10a is of a multichamber design wherein aunitary housing is formed of two portions. A molded rear or body portion105 is preferably formed of a light-colored opaque plastic, and containsa number of baffles, walls and posts which extend to a common frontplane and define the internal structure of chambers, ribs, ports andsupporting elements much as previously discussed in relation to FIG. 1.Front panel 115 is formed of a transparent sheet of substantiallyuniform thickness. The body portion and the from panel are preferablyassembled by linear vibration welding. For this purpose, slightprotruding ridges may be formed in the inner face of the front panel toalign with and seal to the linear wall portions of the body securely.The front panel, as illustrated, has a graphic mask 130 printed thereondefining a plurality of windows, status indicators and calibration ormeasuring indicators.

Among the "windows" defined by graphic mask 130 are a manometer window134, a water seal window 133, and a collection chamber window 132, eachof which is aligned over the corresponding chamber of the housing.Preferably fill lines 134a, 133a in the windows mark the appropriatewater level to achieve a suitable suction level and water seal. In theillustrated embodiment, an additional window 132a is aligned over asecond fluid collection column, which as discussed in greater detailbelow, is preferably at least partially isolated from the normalinlet-filtration-outlet circuit. Each of the windows preferably has agrommet port 17a, 17b, 17c which may be used, in the case of windows133, 134 to fill or replenish the water column, and in the case ofwindow 132 to sample the collected fluid.

In addition to the aforesaid window structures, the graphic overlay 130includes an opaque region 135 which, as described in greater detail inregard to FIG. 4, covers a portion of the drain having a large areagross blood filter, through which fluids drained from the patient fallto reach the collection chamber. Preferably, opaque region 135, or oneof the columns or regions below it, contains a printed chart, e.g., aset of blank lines against a light matte ground, to write a schedule offluid recovery, or a record of fluids transferred to a vessel 50 or toan infusion conduit. In opaque region 135 a series of small clearwindows 136a-136f provide an indication of the level of fluidaccumulated inside the drain over the gross filter, as described below,of which the general location and shape is indicated at 138. The levelindicated by windows 136a-136f depends on the rate of blood collection,and on the volume of accumulated clots. When the level continues torise, unfiltered blood overflows into the column of window 132b.

A pedestal 139 is rotatably attached to housing 105, and rotates outfrom the general plane of the drain device to provide, together withface plate protrusions 139a, 139b, a base and stabilizing feet tosupport the drain upright on a surface. An alternate means of support isto provide hooks from a pair of brackets 141 (of which one is visible inthe figure) to hang the drain from a frame.

It will be observed that each of windows 133, 134 has a narrow and awide portion. These portions lie over narrow and wide arms of therespective water columns. Another feature visible in FIG. 3 is that thehousing of drain 10a is not of uniform front-to-back depth. For example,it will be seen that outlet 19a is located in a lower portion of thedrain having a chamber thickness approximately half that of the upperportion. This geometry of differing chamber depths efficiently channelsfluid to a lower collecting sump region. Other localized differences ina chamber depth or thickness, described in greater detail below,cooperate to provide a stable and highly uniform suction drain device.

FIG. 4 is a sectional view of the molded rear body portion 105 of drain10a of FIG. 3, taken along a plane parallel to and slightly behind thefront panel 115. To aid in visualizing the correspondence with featuresof FIG. 3, the fill lines 133a, 134a and grommets 17a, 17b, 17c areindicated on the Figure, although they are features of the panel 120.The pierceable sample/fill grommets 17 may alternatively be located inapertures in the rear wall of the body portion 105 in the positionsindicated in FIG. 4. Certain details of FIG. 4 are also intended asschematic rather than as exact sections. For example, the float ball330, described below, is simply shown in a perspective view foremphasis.

Drain 10a, like the basic embodiment of FIG. 1, includes an internalstructure of walls which separate the interior into three chambers,namely a manometer chamber 314, a water seal chamber 313, and a fluidscollection chamber 312, which are laid out in a series low path, withthe vacuum source connected to port 18 between chambers 314 and 313.

A principal feature of the illustrated device is that it achieves stableand safe suction levels despite changing conditions at the patient inletport 11, and at the outlet/reinfusion port 19a. To this end, the wallsdefining the three chambers and the passages therebetween have thefollowing properties.

Manometer chamber 314 includes a two arm U-shaped water column wherein afirst arm 320 which is open to the atmosphere via plug 15 has across-sectional area substantially below (e.g., less than one tenth)that of the second arm 321 which communicates with vacuum port 18. Suchan arrangement limits the amount of water which is drawn from column 320into column 321 when suction starts, so that the resting height of thewater column 321 accurately reflects the intended suction level. Itfurther limits the amount of water which can be blown from column 321into column 320 in the event of a pressure surge in the interior of thedrain, so that short time pressure fluctuations are modulated by theexpenditure of energy in pushing water along the column, and abruptwater losses which might disable the device do not occur. A thirdsub-chamber 322 communicates with arm 321 via lateral opening 324 in adivider wall 325. This sub-chamber effectively doubles the fluid-holdingcapacity of the manometer chamber, yet is spaced out of the air flowpath between the bubble-former 110 and the vacuum port 18, so that waterin the sub-chamber is shielded from the evaporative losses due toairflow through chamber 514 which would otherwise regularly degrade theaccuracy of the suction setting. This multi-subchamber arrangementstabilizes the suction level over the long term, as well as providing alarger buffer volume to prevent fluid loss from pressure back-surges.

As in the embodiment of FIG. 1, a plurality of curved baffles (notnumbered) in the upper portion of the manometer chamber returncondensate to the water column.

The volumes of water required to achieve a given suction level in aprototype embodiment are set forth in the following table of manometerfill volumes. It will be seen that the higher suction levels areachieved with a more than proportionately larger volume of water.

                  TABLE I    ______________________________________    Desired Suction Approximate    Pressure        cc Volume    ______________________________________    -20 cm H.sub.2 O                    320 cc    -15             180 cc    -10              80 cc    -5               38 cc    ______________________________________

The water seal chamber 313 similarly includes a pair of arms ofimbalanced cross-sectional area, 315, 316 with the smaller-section arm316 communicating via a reflux structure 317, a tortuous path 318 and abaffled port 319 with the blood collection chamber 312. As with the armsof the manometer chamber, the smaller arm 316 preferably has across-sectional area which is ten percent or less times that of thelarger arm 315. At the top of am 316, however, the portion of the armcontaining the reflux structure is enlarged so that, in the event anextreme underpressure condition should occur in the collection chamber312, the fluid from arm 315 may be accommodated within arm 316 and willnot be drawn through port 319 into the collection chamber.

In the event that a rush of water is sucked up arm 316 toward port 319,a plurality of turning baffles 317a, 317b placed in the path serve tocatch the rising column and deflect back the moving water, thus usingthe moving fluid's own energy to slow the pressure-induced surge, andthereby accommodating extreme pressure surges in the collection chamberwithout disabling the drain device. Such deflection keeps the water sealintact under broader conditions, and the narrow column 316 is of adimension such that bubbles which have entered from column 315 may bedrawn back down the column, as in a capillary column. The arrangement ofbaffle structure, tortuous path and port 317, 318, 319 is such thatfluid from the water seal does not generally reach the collectionchamber, and air which may be drawn through the seal during a shortviolent spasm is re-entrained in the normal evacuative flow towardsuction port 18 when the pressure levels return to normal. Thisconstruction is generally adequate to prevent contaminants from enteringthe collected blood. Moreover, the invention further contemplates theprovision of a filtered pressure relief valve (not illustrated) as invalve 40 of FIG. 1.

A float ball 330 rides in column 316 between two permanent posts 331,332 formed in body portion 105, so that the level of the float providesan indication of an anomalous underpressure in chamber 312, visiblethrough window 133 (FIG. 3). When the ball indicates an anomalously highsuction in the collection chamber, the valve 40 may be actuated, or thesuction will be automatically lowered by the passage of air from columns315, 316.

The third major sub-chamber, the collection chamber portion 312, of thisembodiment of a drain device is defined by the outer contours of themolded body portion 105 as well as by an internal wall 335 which extendsfor the entire height of the drainage device. Wall 335 separates thecollection chamber 312 from water seal 313, so that the two chamberscommunicate only at port 319 as described above. Port 319 has across-sectional area of approximately one-half square centimeter in theprototype device. The total volume enclosed by the body 105, 115 of thatprototype is approximately three liters, comparable to the volume of thepleural chamber. Of this amount, collection chamber 312 constitutes twoor more liters. While the patient connection at port 11 is a largediameter thoracotomy tube which can transmit fairly abrupt pressureimpulses to chamber 312, port 319 limits the attainable flow rates andthus modulates pressure impulses which are initiated on either side ofthe port.

Between the chamber-defining wall 335 and the outer side wall 336, oneor more partial or complete intermediate walls 337, 338, which areintegrally formed with the housing body portion 105, separate chamber312 into sub-chambers 341, 342 and 343 as discussed below. Theintermediate walls 337, 338 also support a large-area fall-throughfiltration element 345 below inlet 11, and extend to one or more upperwall portions 337a, 338a which provide an impoundment for fluids whichhave not passed through the filtration element 345.

As shown, a fluid deflector 347 spaced below the fluids inlet 11channels the incoming fluid so that it falls straight downward into theupper portion 341a of the extreme right sub-chamber 341, onto filter345. Filtered blood then seeps through. This fall-through filterarrangement minimizes mechanical trauma to the blood. Filtration element345 is a large area gross filter, such as a fabric or an open-poresponge filter, which is effective to remove clots and gross particlesfrom the incoming fluids. It may be treated with an anticoagulatingagent to pre-process the fluids passing through it. The filtered fluidsthen pass to the lower portion of chamber 341 where the back portion ofthe body angles forwardly to form a portion of lesser front-to-backdepth constituting a collection sump at outlet port 19a.

When the drain receives an unusually large flow of fluids or the filter345 becomes blocked with clots, the incoming fluids are impounded bywall 337a and eventually overflow into the space 342a between upperwalls 337a and 338a. The overflow fluids contact a fresh area of thefilter 345, through which they pass to chamber 342. Lower chamber 342also communicates directly with sump region 350 and thus with the outletport 319a.

Further, if the rate of fluid intake or amount of clots causes theimpounded fluids in the space 342a to overflow, they pass over the topof wall 338a. In that event, the fluids pass without being filtered intoan overflow collection sub-chamber 343 of chamber 312. The level in thefilter impoundment space 342a is visible through the filter/flow statuswindows 136a-136f (FIG. 3), so that an excessive bleeding rate orclotting condition is easily detected by hospital personnel. Theprovision of an open, fall-through filter in this manner preventsback-up of fluids in the thoracotomy inlet tube from the patient, acommon cause of tamponade, while still providing prefiltration ofscavenged blood. This is a distinct improvement over a closed sock-typefilter as used in prior art devices.

As shown in the Figure, a passage 351 is provided between chamber 343and the sump area 350. In alternative embodiments, this passage may beomitted so that the overflow fluid is fully isolated. The windows 132,132b (FIG. 3) may provide separate graduated fluid volume scales 132c,132d, with the graduations on scale 132c representing the volume inchambers 341 and 342, and those of scale 132d representing theunfiltered volume in chamber 343.

It will be seen that the structure of walls, baffles and ports justdescribed results in the provision of a suction drain vessel whereinbidirectional pressure fluctuations are substantially compensated, andabrupt pressure impulses are modulated to more gradual perturbationsthat do not interrupt the functioning of the device. A further featureof note is that normal suction draws are established such that thediffusion path to the collected blood is relatively isolated. FIG. 13illustrates the normal directions of flow in the device of FIG. 4.

From inlet 11, airflow, if any, is normally along the top of chamber312, toward port 319. Blood entering at port 11 thus has a relativelylow probability of encountering airborne contaminants, and it fallsdownward into chamber 341 or 342, where it is isolated from moving air.Thus, in the rare event air from water seal column 315 is drawn pastport 319, it is unlikely to result in significant contamination, and thecollected blood will be safe for reinfusion for at least the duration ofa surgical operation or procedure.

FIG. 4 also illustrates a preferred outlet structure 185 attached toreinfusion/outlet port 19a. Port 19a is located at the lowest point ofthe drain, and has an large bore PVC infusion tube 180 attached thereto,with a pinch clamp 21. At the end of tube 180, an IV spike port 181having a diaphragm closure 182 and reclosable cap 183 allows the sterileconnection to transfer vessel 50 or to a conventional infusion pump orline. The position of port 19a assures that collected blood is entirelydrawn out, thus minimizing the risk of contamination of the collectedfluid. The large bore IV tubing allows fast delivery of the collectedfluid.

FIG. 5 shows a back view of the molded body portion 105 of the two-piecehousing of drain 10a. The rear wall portion 105 consists of anarrangement of substantially rectangular panels each of which definesall or a portion of the rear wall of one or more of the sub-chambers orwater columns described in respect of FIG. 4. In this preferredembodiment, each of the substantially rectangular panels lies parallelto the front panel at a depth "d" which is one of a few discrete values.In the illustrated prototype embodiment, which has an overall thicknessor chamber depth of approximately two inches, the depth values A, B, C,D, E or F are given in the following table.

                  TABLE II    ______________________________________           Depth "d"                   Inches    ______________________________________           A       1/4           B       1/2           C       1           D       11/2           E       13/4           F       2    ______________________________________

The regions marked "S" in FIG. 5 are slanted back wall portions whichlead from one chamber depth to a different chamber depth.

This back wall structure has been found to provide a particularlyadvantageous set of pressure response characteristics for the columnsand chambers defined thereby, as well as providing a distinctive andvisually pleasing outer form quite different from the awkward box-likeappearance of conventional chest drain devices.

FIGS. 6-9 show additional external views of the presently preferredprototype drainage device, illustrating in detail the contours andlocations of the various wall, port, support and other features formedin the molded housing in this preferred construction. Among otherdetails, these drawings show clearly the relatively large patient inletport 11 (FIGS. 6, 7) which connects to and is preferably pre-packagedwith, a large-diameter flexible latex thoracotomy tube. Thetransfer/infusion port 19a (FIGS. 7, 8), by contrast, connects to asmaller blood-compatible PVC tube. Preferably, the drain device ispre-packaged with a short, e.g., half-meter length of such tubingmounted on the port 19a, and having a sealed diaphragm-type spike portat its end. FIGS. 8, 9 show a cylindrical shaft 151 with stops 152aformed on the housing 105. Pedestal 139 is rotatably secured on shaft151 by the stops, which also serve as detents to lock the pedestalperpendicular to the plane of the device when the pedestal is rotated.

One or more of the foregoing features of the drain device are alsoadvantageously incorporated into different drain devices illustrated inFIGS. 10-12.

FIG. 10 shows another drain device 10b which is specially adapted tocollect fluids from several sites via plural patient fluid inlet ports11a, 11b. In this device, the manometer and water seal chamber structureare substantially identical to those illustrated in FIGS. 3-5, but theinlet ports 11a, 11b lead to different collection chambers so that thevolume of fluid collected from each site may be separately ascertainedfrom the graduated windows 161, 162, 163. In this embodiment no outletport or gross filter is provided, and the drain serves to collect fluidand monitor collected fluid levels. It is thus not intended for fluidreinfusion. A principal collection chamber under inlet 11a has twocolumns located behind windows 161 and 162, respectively. A continuouswall similar to wall 337 of FIG. 4, but extending entirely to thebottom, separates the two columns and assures that first one columnfills and then overflows to fill the other column. Behind window 163 asingle isolated secondary collection column receives fluids only frominlet 11b, and separately indicates their volume.

FIG. 10A shows another drain embodiment 10c having two patient inlets11b, 11a. In this embodiment, a filter and outlet port 19a are providedfor prefiltering and reinfusion of the fluid collected via inlet 11a,which is the primary inlet for mediastinal fluid drainage. Secondaryinlet 11b provides unfiltered collection from a secondary site, such asone at the apex of the lung, into a preferably isolated separategraduated column.

FIG. 11 shows another drain unit 10d with a single inlet and no outlet.In this embodiment, first and second inner walls define successiveoverflow paths to fill first one column, then the second, then thethird. Again no gross filter or fluid outlet is provided.

FIG. 12 shows another drain unit 10d according to the invention. Thisdrain is a pediatric drain, and employs the same water column structureas the preceding devices. It includes neither a gross filter nor anoutlet port. The inner walls corresponding to walls 337, 338, 335 ofFIG. 4 are modified to define a single collection column located behindwindow 165, and the column is dimensioned such that its full heightcorresponds to a fluids volume of only approximately two to five hundredcubic centimeters. A broad portion 170 of the panel covering the deadspace between the collection column and the water seal has a brightengaging picture, represented in phantom, thereon.

Thus, the drain device described in relation to FIGS. 3-9 is adapted,with minor changes of straight interior wall portions and differentprinting on the front face, to provide a stable and sterile suctiondrainage device for a variety of drain applications and autologous bloodcircuits.

It will be appreciated that numerous of the features shown can be usedindependently of others and in a variety of drain device forms andstructures. It will thus be seen that a chest drain device according tothe invention efficiently attains the objects set forth above as well asthose made apparent from the preceding description. Since changes may bemade in the illustrated device without departing from the scope of theinvention, all matter contained in the above description or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

Having described the invention, what is claimed as new and secured byletters patent is:
 1. A vessel for aspirating and collecting vitalfluid, such vessel comprisingi) a plurality of walls formed of polymericmaterial and defining an interior chamber having at least first, second.Iadd.and .Iaddend.third openings therein adapted for communication withthe atmosphere, with a suction source, and with a vital fluid collectiontube, respectively, said interior chamber being subdivided to provide abuffered volume of at least first, second and third successiveintercommunicating sub-chambers having said respective first, second andthird openings . .herein.!. .Iadd.therein.Iaddend., ii) first and secondwater columns included in said first and second sub-chambers forproviding during normal operation first and second pressuredifferentials in said interior chamber effective to establish aunidirectional draw at each said first and third opening toward saidsecond opening while correcting changes in pressure to maintain adesired subatmospheric pressure range in said third sub-chamber, iii)said vessel having a volume and interior shape of intercommunicatingpassages between sub-chambers including . .a self-bailing structureabove said second water column comprising means for intercepting andreturning to said second water column water rising and water entrainedin air bubbles, while bidirectionally allowing free passage of air pastsaid self bailing structure, and a port above said self-bailingstructure between said second and third sub-chambers, for absorbingenergy of abrupt pressure variations of said third sub-chamber, andbeing operative with said water columns to effectively maintain uniformsaid desired subatmospheric pressure range.!. .Iadd.means in upperportion of said vessel extending from said second to said thirdsub-chamber and configured to allow passage of air back and forththrough said upper portion while protecting integrity of the water sealduring patient breathing cycles and during application of suction due tooutflow of collected fluids from said collection chamber.Iaddend., saidthird sub-chamber also having a fourth opening at a lower portionthereof and a filter disposed in a flow path between said third andfourth openings, wherein said fourth opening is a closable . .outlfow.!..Iadd.outflow .Iaddend.opening having a sterile connection for couplingto flow means, and flow means for fluid interconnection with said fourthopening to deliver collected vital fluid therefrom, whereby fluidscollected in said third sub-chamber effectively define a further fluidseal and vital fluid collected in said third sub-chamber may becontinuously drawn from below the surface at said fourth opening forreinfusion without introducing pressure irregularity in said thirdsub-chamber or interruption of said aspirating and collecting.
 2. Avessel according to claim 1, wherein one of said plurality of wallsforms a face of said third sub-chamber and is transparent and the vesselfurther comprises an opaque mask defining a window array selectivelypositioned on said face to display the volume of filtered vital fluids.3. A vessel according to claim 2, wherein said window array includeswindows displaying portions of said water columns indicative of saidfirst and second pressure differentials.
 4. A vessel according to claim3, further comprising a float ball in a said water column and visiblethrough a window for indicating an anomalous suction condition in saidthird chamber.
 5. A vessel according to claim 1, wherein said walls areconstituted by two opposed wall pieces joined in a generally planarregion and along generally linear strips within said planar region, saidtwo opposed wall pieces being assembled by linear vibration weldingalong said strips.
 6. A vessel according to claim 1, wherein said firstwater column constitutes a manometer chamber having first and secondbranches communicating with said first and second openings,respectively, and wherein one of said branches is constituted bya firstfluid body of a first cross-sectional area located in a direct air flowpath between said first and second openings, and a second fluid body ofsecond cross-sectional area located in fluid communication with saidfirst fluid body and out of said air flow path, whereby airflow inducedevaporative loss from said manometer chamber is reduced therebyeffecting more stable pressure regulation.
 7. An improved system fordrainage of fluids from the thoracic cavity of a patient, of the typewherein the system includes a closed vessel having, in sequence, amanometer chamber for setting a desired vacuum underpressure, a waterseal chamber, and a collection chamber, said collection chamber havingan inlet port at an upper region thereof and a pooling sump at a lowerregion thereof, wherein the improvement comprisesa filter in a fluidpath between said upper and lower regions for removing gross structuresfrom thoracic cavity fluid aspirated through said inlet as it travels tosaid pooling sump without obstructing flow from said inlet port, aclosable transfer port defining an outflow path through an outer wall ofsaid collection chamber at a lower region of said sump below the surfaceof fluid collected therein, and means for sterile interconnection of areinfusion device to said closable transfer port so that collected bloodmay be quickly withdrawn from below the surface of the collected fluidalong said outflow path, wherein the water seal chamber and thecollection chamber communicate with each other along a direct paththrough an open port interconnecting these two chambers to continuouslyequalized subatmospheric pressure therein, whereby collected fluids insaid collection chamber are available for direct reinfusion by directlywithdrawing fluid from said transfer port without interrupting theaspiration of thoracic fluid through said inlet.
 8. The improved systemof claim 7, further comprising a transfer vessel attached to saidtransfer port, said transfer vessel including means within the transfervessel for establishing a second vacuum underpressure, so thatwithdrawal of collected fluid is accomplished by a single line whichinterconnects said transfer vessel and said transfer port.
 9. Theimproved system of claim 8, wherein the transfer vessel has amicroporous vent and a cover closing the vent, so that with the coverclosed the vessel develops suction for effecting transfer of collectedfluid to the transfer vessel, and with the cover open fluids transferredto said transfer vessel may be gravity infused from said vessel directlyto a patient.
 10. A disposable autoinfusion apparatus for the collectionof fluids from the thoracic cavity of a patient and reinfusion thereof,said apparatus comprisinga continuously aspirating collection unitcomprising first, second and third serially-connected chambers, whereinsaid first chamber includes vacuum setting means for connection to avacuum source and setting of a desired underpressure, said secondchamber includes a water seal interposed between said first and thirdchamber, and wherein said third chamber includes an inlet for fluid flowconnection to the thoracic cavity, an outlet in fluid flow communicationwith said second chamber, a lower pooling region for the pooling offluid aspirated through said inlet, and also includes first and secondaccess ports at said pooling region, said first access port beingadapted for aseptically withdrawing a fluid sample from said poolingregion and said second access port defining a conduit opening at asubsurface level of said pooling region, said third chamber furtherincluding a gross filter located below said inlet above said poolingregion in an open flow path having an overflow path such that bloodentering the inlet is filtered as it passes to the pooling region whileblockage does not occur at said inlet and means for selectively drawingfluid from said second access port and reinfusing said fluid whilemaintaining said desired underpressure in said collection chamber,whereby said pooled fluid from said collection unit is withdrawn frombelow the surface of fluid collected in said third chamber and isreinfused without interrupting collection from the thoracic cavity. 11.The apparatus of claim 10, wherein said means for selectively drawingfluid comprises a drain tube connecting said second access port to amechanism for withdrawing and for reinfusing collected fluid from saidpooling region.
 12. The apparatus of claim 11, wherein said means forselectively drawing fluid comprises a flexible vessel attached to saidsecond access port, said flexible vessel having an interior springmechanism effective to create an internal suction by beating against thevessel walls, said flexible vessel further having a microporous ventwhich is opened to allow the vessel when disconnected from the accessport to be connected for gravity-infusion of its contents into apatient.
 13. The apparatus of claim 10, wherein said overflow pathpasses through a gross filter.
 14. The apparatus of claim 13, furthercomprising a barrier defining a further overflow path which isunfiltered.
 15. The apparatus of claim 13, further comprising means fordisplaying a filter status condition.
 16. The apparatus of claim 15,wherein the filter status condition includes an indication of fluidback-up.
 17. The apparatus of claim 10, wherein said third chamberincludes an upper chamber including said inlet, a lower chamberincluding said second access port, and a gross filter defining apermeable barrier between said upper and lower chambers, said upperchamber further having a vertically extending wall defining an overflowopening for the passage of unfiltered fluid from the upper chamber whenthe gross filter is blocked, thereby preventing vacuum blockages andconsequent obstruction of flow through said inlet.
 18. A drain devicefor draining blood and fluids from the thoracic cavity of a patient,such device comprising a multichamber vessel of a total volumecomparable to the pleural volume of the patient, said device including amanometer for establishing a predetermined suction level, and whereinthe multichamber vessel includesi) a collection chamber having an inletport for connection to the patient, an outlet, and a pooling region, anda water seal U-column having an inlet port connected to said collectionchamber outlet, and an outlet at the manometer to normally sustain apredetermined suctional draw in said collection chamber toward saidmanometer, and wherein said water seal inlet port is spaced from saidwater seal column by a baffled path, and has dimension sufficientlysmall to modulate abrupt pressure variations in said collection chambercaused by patient spasms, thereby effectively preventing back flow fromsaid water seal to said collection chamber, whereby blood collected insaid collection chamber is substantially isolated from contaminationfrom said manometer and said water seal U-column and remains suitablefor reinfusion, said water seal inlet port being open so thatsubatmospheric pressure in said water seal is continuously equalizedwith subatmospheric pressure of the collection chamber, the outlet ofthe collection chamber being located at a subsurface level of thepooling region for withdrawal of collected blood and direct reinfusionof blood to the patent.
 19. A drain device according to claim 18,further having at least one additional collection chamber and anadditional inlet port separately communicating with said additionalcollection chamber, said water seal and manometer chambers being insuction communication with said at least one additional chamber wherebyfluids from plural patient sites may be simultaneously and separatelycollected and monitored by said device.